984 resultados para Point-Contact
Resumo:
The effect of mixture of seeds of Brachiaria brizantha, cv. Marandu, with different sources, granulometry, and phosphatic fertilizer doses during various periods of exposure on the physiological potential of the seeds has been assessed. The treatments consisted in seed exposure during periods of 0, 3, 6, 12, 24, 36, 48, 72, 96, and 120 h to the following fertilizers: ground granulated single superphosphate (SS), and powdered (SSp); and ground granulated ammonium monophosphate (AMP), at doses of 40 and 80 kg P2O5 ha-1. Tests of germination, tetrazolium, moisture content, and vigor (first count, electrical conductivity, emergence, emergence speed, and fresh mass of seedlings) were performed. It has been concluded that seed physiological potential of B. brizantha cv. Marandu is reduced with increase on the exposure period to phosphatic fertilizer. Such effect, however, is dependent on the product source, granulometry, and dose. SSp was the most harmful to seeds, followed by SSp and AMP, respectively. Moreover, considering a 60% germination rate as acceptable, it may be inferred that seeds can be kept in contact with AMP and SSp, in dose of 80 kg of P2O5 ha-1, respectively, for periods of 71.2 and 16.2 hours.
Resumo:
This dissertation describes an approach for developing a real-time simulation for working mobile vehicles based on multibody modeling. The use of multibody modeling allows comprehensive description of the constrained motion of the mechanical systems involved and permits real-time solving of the equations of motion. By carefully selecting the multibody formulation method to be used, it is possible to increase the accuracy of the multibody model while at the same time solving equations of motion in real-time. In this study, a multibody procedure based on semi-recursive and augmented Lagrangian methods for real-time dynamic simulation application is studied in detail. In the semirecursive approach, a velocity transformation matrix is introduced to describe the dependent coordinates into relative (joint) coordinates, which reduces the size of the generalized coordinates. The augmented Lagrangian method is based on usage of global coordinates and, in that method, constraints are accounted using an iterative process. A multibody system can be modelled as either rigid or flexible bodies. When using flexible bodies, the system can be described using a floating frame of reference formulation. In this method, the deformation mode needed can be obtained from the finite element model. As the finite element model typically involves large number of degrees of freedom, reduced number of deformation modes can be obtained by employing model order reduction method such as Guyan reduction, Craig-Bampton method and Krylov subspace as shown in this study The constrained motion of the working mobile vehicles is actuated by the force from the hydraulic actuator. In this study, the hydraulic system is modeled using lumped fluid theory, in which the hydraulic circuit is divided into volumes. In this approach, the pressure wave propagation in the hoses and pipes is neglected. The contact modeling is divided into two stages: contact detection and contact response. Contact detection determines when and where the contact occurs, and contact response provides the force acting at the collision point. The friction between tire and ground is modelled using the LuGre friction model, which describes the frictional force between two surfaces. Typically, the equations of motion are solved in the full matrices format, where the sparsity of the matrices is not considered. Increasing the number of bodies and constraint equations leads to the system matrices becoming large and sparse in structure. To increase the computational efficiency, a technique for solution of sparse matrices is proposed in this dissertation and its implementation demonstrated. To assess the computing efficiency, augmented Lagrangian and semi-recursive methods are implemented employing a sparse matrix technique. From the numerical example, the results show that the proposed approach is applicable and produced appropriate results within the real-time period.
Resumo:
The aim of this study was to examine how to support breastfeeding of preterm infants immediately after birth in the delivery ward, during their hospital stay in a neonatal intensive care unit (NICU), and at home after hospital discharge. Specifically, the role of early physical contact, maternal breastfeeding attitude, and an internet-based peer support group were investigated. The delivery ward practices concerning the implementation of early physical contact between a mother and her infant admitted to a NICU were examined by a structured survey in two hospitals. An Internet-based, breastfeeding peer-support intervention for the mothers of preterm infants was developed and tested in a randomized controlled design with one year follow-up. The main outcomes were the duration of exclusive and overall breastfeeding, expressing milk, and maternal attitude. In addition, the perceptions of mothers of preterm infants were investigated by analyzing the peer-support group discussions with a qualitative approach. The implementation of early physical contact was different between the two hospitals studied and was based more on hospital routines than the physiological condition of the infant. Preterm infants, who were born before a gestational age (GA) of 32 weeks, were hardly ever allowed to have early contact with their mothers. Both, a higher GA and early physical contact predicted earlier initiation and increased frequency of breastfeeding in the NICU. A maternal breastfeeding-favorable attitude predicted increased frequency of breastfeeding in the NICU and also a longer duration of overall breastfeeding. The actual duration of breastfeeding was, however, shorter than the mothers intended in advance. The internet-based, peer-support intervention had no effect on the duration of breastfeeding, expressing milk, or maternal attitude. The participating mothers enjoyed the possibility of sharing their experiences of preterm infants with other mothers in similar situations. Some of the mothers also experienced being given useful advice for breastfeeding. Based on the mothers’ discussions, a process of breastfeeding preterm infants was created. This included some paradoxical elements in the NICU where, for example, breast milk was emphasized over breastfeeding and support in the hospital varied. Hospital discharge was a critical point, when the mothers faced breastfeeding in reality. Over time, the mothers assimilated their breastfeeding experience into part of being a mother. The care practices related to early physical contact in delivery wards need to be re-evaluated to allow more infants to have a moment with the mother. Maternal attitude could be screened prenatally and attitude-focused interventions developed. Breastfeeding support in the NICU should be standardized. Internet-based breastfeeding peer-support intervention was feasible but additional research is needed.
Resumo:
The literature on agency suggests different implications for the use of export intermediaries. However, only few studies provide a view on import intermediaries. This thesis tries for its part to fill this research gap by studying the import intermediaries in the EU–Russia trade from a Russian industrial company’s point of view. The aim is to describe import intermediation and explain the need for import intermediary companies in the EU–Russia trade. The theoretical framework of this thesis originates from an article by Peng and York (2001), in which they study the performance of export intermediaries. This thesis applies resource-based theory, transaction cost theory and agency cost theory, following the idea of Peng and York. The resource-based theory approach is utilised for describing an ideal import intermediary company, and transaction cost theory provides a basis for understanding the benefits of using the services of import intermediary companies, while agency cost theory is applied in order to understand the risks the Russian industrial company faces when it decides to use the services of import intermediaries. The study is performed in the form of a case interview with a representative of a major Russian metallurgy company. The results of the study suggest that an ideal intermediary has the skills required specifically for the imports process, in order to save time and money of the principal company. The intermediary company helps reducing the amount of time the managers and the staff of the principal company use to make imports possible, thus reducing the salary costs and providing the possibility to concentrate on the company’s core competencies. The benefits of using the services of import intermediary companies are the reduced transaction costs, especially salary costs that are minimised because of the effectiveness and specialisation of import intermediaries. Intermediaries are specialised in the imports process and thus need less time and resources to organise the imports. They also help to reduce the fixed salary costs, because their services can be used only when needed. The risks of being misled by intermediaries are minimised by the competition on the import intermediary market. In case an intermediary attempts fraud, it gets replaced by its rival.
Resumo:
The amount of Russian tourists in Finland has increased significantly in the past years. The impact of Russian tourism to the Finnish retail trade sector is enormous, since Russian tourists often spend a lot of money particularly on shopping. Shopping tourism is mainly focused in the near border cities, such as Imatra and Lappeenranta, and in addition in Helsinki metropolitan area. The purpose of this study is to map the attitudes and perceptions of the sales personnel who are working in the Finnish retail trade sector towards Russian customers and to discover which elements affect these attitudes. The theories in this study are based on cultural elements and elements related to sales behavior and performance. Cultural differences between Finland and Russia, cultural distance and cultural intelligence form the cultural aspect of this study. Customer orientation vs. sales orientation (SOCO), adaptive selling, selling skills and job competency, salesperson’s affect and empathy toward customers, and job autonomy form the elements concerning sales behavior and performance. Furthermore, the attitude – behavior link, based on social psychology is addressed. A survey was conducted in two retail trade chains operating in Finland. These retail companies have stores and department stores in different geographical areas in Finland and the survey was conducted in altogether 19 cities. In addition to the theories that were discussed, two expert interviews were conducted in order to get a deeper understanding of the phenomenon at hand. Moreover the interviews helped in the formulation of the hypotheses and the questionnaire design. The questionnaires were sent directly to the stores, where they were placed so that they were available for the sales personnel. Altogether 487 usable responses were collected. The returned questionnaires were analyzed with IBM SPSS 21 statistics program. The results of this study indicated that the attitudes toward Russian customers are more negative compared to other foreign customers. However, the respondents’ attitudes toward and perceptions of Russian customers varied a lot. From the background variables age, education level, length of employment in current workplace, and length of experience in customer service had an effect on the attitudes of the respondents. In addition, the perceptions of Russian customers were more positive in the Eastern Finland compared to Helsinki metropolitan area. The cultural elements; cultural knowledge, cultural distance and cultural intelligence all affected the attitudes of the respondents. From the elements related to sales behavior and performance customer orientation, salesperson’s affect and empathy toward customers, and perceived job autonomy had an effect on the attitudes
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[Acte. 1716-03-17. Paris]